Yarn-treating jet

ABSTRACT

A yarn-treating jet comprising a body and a flat cover clamped together and having two air conduits of equal rectangular cross section for directing heated fluid on a yarn advancing through a passage in the surface of the jet body contiguous with the cover. The passage includes an expansion zone located downstream from the air conduits which has an entrance larger than its exit for the purpose of providing an extended static pressure zone in the jet to improve heat transfer between the heated fluid and the yarn. The cover plate has a guiding surface adjacent the exit of the jet for diverting fluid and entrained yarn outwardly away from the jet exit.

United States Patent Yngve 1 Feb.v 1, 1972 [54] YARN-TREATING JET Primary Examiner-Louis K. Rimrodt [72] Inventor. Paul Wesley Yngve, Wilmington, Del. Atmmey HOward p. west, Jr [73] Assignee: E1. du Pont de Nemours and Company,

Wilmington, Del. [5 7] ABSTRACT Filedl 1970 A yarn-treating jet comprising a body and a flat cover clamped Appl. No.: 17,140

together and having two air conduits of equal rectangular cross section for directing heated fluid on a yarn advancing through a passage in the surface of the jet body contiguous with the cover. The passage includes an expansion zone located downstream from the air conduits which has an entrance larger than its exit for the purpose of providing an extended static pressure zone in the jet to improve heat transfer between the heated fluid and the yarn. The cover plate has a guiding surface adjacent the exit of the jet for diverting fluid and entrained yarn outwardly away from the jet exit.

8 Claims, 5 Drawing Figures Pmmwrm m2 3.636291 sum 1 or 5 HEATED FLUID F I G. 3

' INVENTOR PAUL, WESLEY YNGVE ATTORNEY PATENIED FEB? I972 SHEEI 2 BF 3 FIG- AXIAL DISTANCE ALONG YARN PASSAGE (INCHES) INVENTOR PAUL WESLEY YNGVE MM W W,

ATTORNEY PRESSURE (PSI) PATENTEDFEBI !972 3,638,291

SHEEI 3 HF 3v IS- I AXIAL DISTANCE ALONG YARN PASSAGE (INCHES) INVENTOR PAUL WESLEY YNGVE ATTORNEY YARN-TREATING JET BACKGROUND OF THE INVENTION This invention relates to a jet device for treating yarn from synthetic filaments with a heated fluid to introduce random curvilinear crimp. In particular, the invention has to do with a two-piece bulking jet, one piece containing the critical fluid and yarn-treating passages which provide an extended zone for treating the yarn under increased fluid pressure to improve its dye uniformity and the other piece containing a guiding surface to divert fluid exiting from the jet to reduce tangling of the treated yarn.

The bulking jets of the present invention are useful for the types of yarn treatments disclosed by Clendening in U.S. Pat. No. 3,169,296 to produce bulked textile products as disclosed by Breen et al. in U.S. Pat. No. 3,186,155.

A large number of prior art jet types having conical or cylindrical bulking chambers and fluid exit sections are subject to spiral flow patterns which can twist the yarn erratically, inhibiting heat transfer and producing zones of low bulk and dyeability. This is a particular problem when such jets are operated at high fluid pressures in an attempt to obtain maximum crimp and entanglement at high productivity rates. Furthermore, at such pressures where the yarn laydown surface is a moving screen apparatus, uniform laydown of the yarn on the screen becomes difficult because the yarn has a tendency to creep upstream before depositing on the screen surface. As a result, this portion of the yarn remains momentarily longer than desirable in the hot fluid stream and is subjected to more heat treatment and turbulent entanglement than other portions of the yarn.

A two-piece bulking jet having critical passage relationships has been described by Coon in U.S. Pat. No. 3,525,134 as use-' ful for yarn treatments disclosed by Clendening as noted above. In addition, Coon discloses that rectangular cross sections for fluid supply and yarn treatment channels minimize detrimental swirling of the treating fluid.

A principal object of the present invention is to provide an improved yarn-texturing jet capable of handling a relatively wide range of heavy-denier yarns at high productivity rates.

Another object of the present invention is to provide an improved yarn-texturing jet having more efficient utilization of the heated treatment fluid.

Another object is to provide a jet which can maintain high treatment pressure without detrimental twisting action.

Yet another object of the present invention is an improved texturing jet providing better control of the yarn as it is deposited on a foraminous surface.

SUMMARY OF THE INVENTION A yarn-treating jet comprising: a body and a cover clamped together; a longitudinal passage recessed in the surface of the body contiguous with the cover through which yarn passes for treatment; a pair of angularly disposed conduits in communication with the passage for directing fluid against opposite sides of the yarn; fluid supply means connected to said conduits; said passage including successively, tapered and cylindrical lengths, an enlarged throat region, an expansion cavity and a continuously expanding rectangular treatment chamber terminating at an exit, said conduits intersecting said throat region in an opposed relationship and having equal rectangular cross-sectional areas, the cross-sectional area of said throat region in communication with said cavity being greater than the cross-sectional area of said cavity in communication with said expanding treatment chamber, said cover having a guiding surface adjacent said exit for deflecting fluid and entrained yarn outwardly from said exit.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. I is an isometric view of the subject jet with the cover removed to show the yarn treatment passage.

FIG. 2 is an enlarged plan view of a portion of the yarn treatment passage of FIG. 1.

FIG. 3 is an elevation of the subject jet positioned above a moving screen surface partially sectioned to show the curved guiding surface in the cover near the exit of the jet.

FIGS. 4 and 5 are respective illustrations of a prior art jet passage configuration and the jet passage configuration of this invention showing fluid pressure profiles of their respective yarn treatment zones. FIG. 4 also has the pressure profile of FIG. 5 superimposed upon it.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to FIGS. 1-3, the jet of this invention is seen to include a body 10 and a flat detachable cover 12 which is secured to the body 10 by a conventional threaded fastener 14 that extends through hole 16 for that purpose. A pair of locating dowel pins 18, 20 in body 10, engage matching cavities (not shown) in cover 12 and serve to align the cover with the body. An internal supply manifold 22 within body 10 furnishes heated pressurized treatment fluid to a pair of angularly disposed conduits 24, 26 of equal cross section which communicate with enlarged throat region 36 of longitudinal yarn passage 28 recessed in surface 29 of body 10 through which yarn 30 passes for treatment. Various types of treatment fluid, such as heated air and inert gas or superheated steam can be used and is supplied to manifold 22.

As best shown in FIG. 2, yarn passage 28 includes successively, tapered and cylindrical lengths 32, 34, an enlarged throat region 36, a triangle-shaped expansion cavity 38 and a continuously expanding treatment chamber 40 terminating in an exit 42. The conduits 24, 26 and passage 28 are of constant depth in body 10. The conduits 24, 26 have uniform equal rectangular cross-sectional areas while passage 28 is seen to have varying cross-sectional areas due to changes in its width along its length.

The relationship of particular cross-sectional areas along the passage 28 are specifically established to provide specific fluid flow conditions within the jet. For example, it has been found that a highly uniform quality bulked yarn is obtained when, in addition to that disclosed above, the following relationships also exist: cylindrical length 34 has a minimum crosssectional area equal to or less than one-half the area of one fluid conduit (e.g., conduit 24) and at the opening 37 leading into expansion cavity 38, the cross-sectional area is greater than that at opening 39 leading from the expansion cavity to the treatment chamber 40. More particularly, the cross-sectional area at opening 37 is more than twice that of one fluid conduit (e.g., conduit 24) while the cross-sectional area at opening 39 is approximately equal to twice that of one fluid conduit. The opening 37 is sized to permit the yarn 30 to open freely without restraint as it passes into cavity 38. The treatment chamber 40 preferably continuously increases in width from opening 39 to exit 42, the included angle being 6 or less. The included angle between conduits 24, 26 is preferably held to about 60.

The entire length of passage 28 is enclosed by cover plate 12, secured to body 10 except for a tunnellike opening 50 in cover 12, substantially perpendicular to yarn line 30 and to the closure plane of the cover near exit 42. A contoured surface 52 having a radius between one and three times the dimension 51 of the opening 50 is provided to deflect a portion of the treatment fluid toward opening 50 for assisting the entrained yarn 30 in that direction for deposit on rotating foraminous surface 54 (FIG. 3).

FIG. 4 schematically illustrates a portion of the yarn passage 28 and conduits 24', 26' of a prior art jet similar to that disclosed by Coon in U.S. Pat. No. 3,525,134. Also shown is a tracing 45 of the static pressure profile along the yarn passage 28' when operated at p.s.i. manifold pressure and normal operating temperatures.

By comparison, FIG. 5 schematically illustrates substantially the same portion of the yarn passage 28 of the jet of the present invention with a tracing 55 of its static pressure profile under the same pressure and temperature conditions as above. Profile 55 is superimposed on FIG. 4 for a ready comparison which shows that under substantially the same operating conditions the jet of this invention extends the zone of increased static pressure for a greater distance along the axis of the yarn passage than the prior art jet of FIG. 4. Comparative test runs have shown advantages for the jet of this invention over the one depicted in FIG. 4 such as improved dye uniformity as well as higher productivity on 1,300-denier yarn and permitting 2,600-denier yarn to be processed in the same jet under the same conditions whereas the jet depicted in FIG. 4 cannot practically process both 1300- and 2,600-denier yarn under the same process conditions.

in the preferred embodiment, the fluid conduits, the throat region, the expansion zone and the expanding treatment chamber are of equal constant depth. The cross-sectional area of the entrance to the expansion cavity is more than twice, while the cross-sectional area of the exit from the cavity is substantially twice, that of one of the fluid conduits supplying heated air to the yarn passage.

The provision of an expansion cavity in the shape of a triangle in a two-piece jet with the particular relationship of fluid supply and yarn treatment passages not only provides an extended static pressure zone in the jet to improve heat transfer to the yarn but also provides a type and degree of fluid oscillation in the cavity quite different from that of conical jet configurations. it has been found that a portion of the treatment fluid at an edge of the fluid stream surrounding the yarn line in the expansion chamber recirculates back toward the base of the triangle, turns inward toward the thread line and impinges on the main fluid stream. its velocity deflects the main stream toward the opposite side of the chamber, whereupon a portion of the fluid on the opposite side of the stream beings to recirculate within the opposite portion of the chamber, turns inward and impinges on the main fluid stream, deflecting it toward the opposite side. This oscillation of the main stream aids in opening the filament bundle and improving the degree and uniformity of heat transfer to the individual filaments.

The previously described yarn laydown problems are overcome by providing a downwardly facing contoured surface 52 in cover 12 which slopes gradually away from a substantially tangential relationship with the treatment chamber 40 and terminates at opening 50. This generates a Coanda effect to divert a portion of the treatment fluid with the entrained yarn 30 in the same direction (i.e., out opening 50) as the moving screen 54. in the preferred embodiment, surface 52 has a 0.25-inch radius and diverts the fluid stream outwardly about from perpendicular.

While the preferred embodiment shows a triangle-shaped cavity, it is to be understood that other configurations will operate satisfactorily. The main consideration in sizing and shaping cavity 38 is that a portion of the treatment fluid recirculates in the expansion cavity 38 and impinges on the main fluid stream with a substantial velocity component perpendicular to the main fluid stream.

Since many different embodiments of the invention may be made without departing from the spirit and scope thereof, it is to be understood that the invention is not limited by the specific illustrations except to the extent defined in the appended claims.

What is claimed is:

l. A yarn-treating jet comprising: a body and a cover clamped together; a longitudinal passage recessed in the surface of the body contiguous with the cover through which yarn passes for treatment; a pair of angularly disposed conduits in communication with the passage for directing fluid against opposite sides of the yarn; fluid supply means connected to said conduits; said passage including successively, tapered and cylindrical lengths, an enlarged throat region, an expansion cavity and a continuously expanding rectangular treatment chamber terminating at an exit, said conduits intersecting said throat region in an opposed relationship and having equal rectangular cross-sectional areas, the cross-sectional area of said throat region in communication with said expansion cavity being greater than the cross-sectional area of said expansion cavity in communication with said expanding treatment chamber.

2. The apparatus as defined in claim 1, said throat region, said cavity, said chamber and said conduits being recessed at the same constant depth.

3. The apparatus as defined in claim 2, said cavity having a width adjacent said throat region greater than the width of said throat region and greater than the width of the cavity adjacent said chamber.

4. The apparatus defined in claim 1, the cross-sectional area of said throat region in communication with said expansion cavity being more than twice the cross-sectional area of one of said conduits.

5. The apparatus as defined in claim 2, the cross-sectional area of said expansion cavity in communication with said expanding treatment chamber being about twice the cross-sectional area of one said conduits.

6. The apparatus defined in claim 1, said cover having an opening there through adjacent said exit and a contoured surface sloping outwardly away from said treatment chamber toward said opening for diverting fluid and entrained yarn outwardly toward said opening.

7. A yarn-bulking jet comprising: a body and a flat cover clamped together; a longitudinal passage recessed in the surface of the body contiguous with the cover through which yarn passes for treatment; a pair of angularly disposed conduits in communication with the passage for directing fluid against opposite sides of the yarn; fluid supply means connected to said conduits; said passage including successively, tapered and cylindrical lengths, an enlarged throat region, a triangleshaped expansion cavity and a continuously expanding rectangular treatment chamber terminating at an exit, aid conduits intersecting said throat region in an opposed relationship ahd having equal rectangular cross-sectional areas, said conduits, said throat region, said cavity and said chamber being recessed at the same constant depth in said surface, the crosssectional area of said throat region in communication with said expansion cavity being greater than the cross-sectional area of said expansion cavity in communication with said expanding treatment chamber, said cover having an opening adjacent said exit and a downwardly facing contoured surface sloping gradually away from a substantially tangential relationship with said treatment chamber and terminating at said opening for diverting a portion of said fluid away from the treatment chamber outwardly toward said opening.

8. The apparatus defined in claim 4, said contoured surface sloping gradually away from said treatment chamber in a radius of from about one to three times the height of said opening. 

1. A yarn-treating jet comprising: a body and a cover clamped together; a longitudinal passage recessed in the surface of the body contiguous with the cover through which yarn passes for treatment; a pair of angularly disposed conduits in communication with the passage for directing fluid against opposite sides of the yarn; fluid supply means connected to said conduits; said passage including successively, tapered and cylindrical lengths, an enlarged throat region, an expansion cavity and a continuously expanding rectangular treatment chamber terminating at an exit, said conduits intersecting said throat region in an opposed relationship and having equal rectangular cross-sectional areas, the cross-sectional area of said throat region in communication with said expansion cavity being greater than the cross-sectional area of said expansion cavity in communication with said expanding treatment chamber.
 2. The apparatus as defined in claim 1, said throat region, said cavity, said chamber and said conduits being recessed at the same constant depth.
 3. The apparatus as defined in claim 2, said cavity having a width adjacent said throat region greater than the width of said throat region and greater than the width of the cavity adjacent said chamber.
 4. The apparatus defined in claim 1, the cross-sectional area of said throat region in communication with said expansion cavity being more than twice the cross-sectional area of one of said conduits.
 5. The apparatus as defined in claim 2, the cross-sectional area of said expansion cavity in communication with said expanding treatment chamber being about twice the cross-sectional area of one said conduits.
 6. The apparatus defined in claim 1, said cover having an opening there through adjacent said exit and a contoured surface sloping outwardly away from said treatment chamber toward said opening for diverting fluid and entrained yarn outwardly toward said opening.
 7. A yarn-bulking jet comprising: a body and a flat cover clamped together; a longitudinal passage recessed in the surface of the body contiguous with the cover through which yarn passes for treatment; a pair of angularly disposed conduits in communication with the passage for directing fluid against opposite sides of the yarn; fluid supply means connected to said conduits; said passage including successively, tapered and cylindrical lengths, an enlarged throat region, a triangle-shaped expansion cavity and a continuously expanding rectangular treatment chamber terminating at an exit, aid conduits intersecting said throat region in an opposed relationship and having equal rectangular cross-sectional areas, said conduits, said throat region, said cavity and said chamber being recessed at the same constant depth in said surface, the cross-sectional area of said throat region in communication with said expansion cavity being greater than the cross-sectional area of said expansion cavity in communication with said expanding treatment chamber, said cover having an opening adjacent said exit and a downwardly facing contoured surface sloping gradually away from a substantially tangential relationship with said treatment chamber and terminating at said opening for diverting a portion of said fluid away from the treatment chamber outwardly toward sAid opening.
 8. The apparatus defined in claim 4, said contoured surface sloping gradually away from said treatment chamber in a radius of from about one to three times the height of said opening. 